http, websocket api handler 추가

server.go

@@ -1,6 +1,7 @@
 package gocommon
 
 import (
+	"bytes"
 	"context"
 	"encoding/gob"
 	"encoding/json"
@@ -699,22 +700,68 @@ func MakeHttpApiHandler[T any](receiver *T, receiverName string) HttpApiHandler
 	}
 }
 
-type HttpApiHandlerContainer struct {
-	methods map[string]apiFuncType
+type HttpApiBroker struct {
+	methods     map[string]apiFuncType
+	methods_dup map[string][]apiFuncType
 }
 
-func (hc *HttpApiHandlerContainer) RegisterApiHandler(receiver HttpApiHandler) {
+type bufferReadCloser struct {
+	*bytes.Reader
+}
+
+func (buff *bufferReadCloser) Close() error { return nil }
+
+type readOnlyResponseWriter struct {
+	inner      http.ResponseWriter
+	statusCode int
+}
+
+func (w *readOnlyResponseWriter) Header() http.Header {
+	return w.inner.Header()
+}
+
+func (w *readOnlyResponseWriter) Write(in []byte) (int, error) {
+	logger.Println("readOnlyResponseWriter cannot write")
+	return len(in), nil
+}
+
+func (w *readOnlyResponseWriter) WriteHeader(statusCode int) {
+	w.statusCode = statusCode
+}
+
+func (hc *HttpApiBroker) AddHandler(receiver HttpApiHandler) {
 	if hc.methods == nil {
 		hc.methods = make(map[string]apiFuncType)
+		hc.methods_dup = make(map[string][]apiFuncType)
 	}
 
 	for k, v := range receiver.methods {
 		logger.Println("http api registered :", k)
-		hc.methods[k] = v
+
+		hc.methods_dup[k] = append(hc.methods_dup[k], v)
+		if len(hc.methods_dup[k]) > 1 {
+			chain := hc.methods_dup[k]
+			hc.methods[k] = func(w http.ResponseWriter, r *http.Request) {
+				body, _ := io.ReadAll(r.Body)
+				defer r.Body.Close()
+
+				wrap := &readOnlyResponseWriter{inner: w, statusCode: 200}
+				for _, f := range chain {
+					r.Body = &bufferReadCloser{bytes.NewReader(body)}
+					f(wrap, r)
+				}
+
+				if wrap.statusCode != 200 {
+					w.WriteHeader(wrap.statusCode)
+				}
+			}
+		} else {
+			hc.methods[k] = v
+		}
 	}
 }
 
-func (hc *HttpApiHandlerContainer) Call(funcname string, w http.ResponseWriter, r *http.Request) {
+func (hc *HttpApiBroker) Call(funcname string, w http.ResponseWriter, r *http.Request) {
 	if found := hc.methods[funcname]; found != nil {
 		found(w, r)
 	} else {